"Not great," was the phrase Richard Allan, Facebook's vice president of policy solutions, used to describe how Zuckerberg's no-show at the hearing looked when asked by a lawmaker. Allan is also a member of the parliament's upper chamber, the House of Lords.
"I think it's important we have this kind of engagement but I also have a role supporting my company as it tries to grapple with the issues that we're talking about today," he said.
Allan added: "And I understand as we're trying to work out where senior officers of the company should be that we should work this out."
The Facebook executive was faced with a grueling session of questioning from international politicians in the British parliament on Tuesday around how it handles user data and privacy.
Lawmakers from Britain, Canada, France, Belgium, Brazil, Ireland, Latvia, Argentina and Singapore questioned Facebook's policy head.
A seat was left vacant beside Allan with a card reading Zuckerberg's name, highlighting the lawmakers' visible frustration with the company for not sending its boss.
"We don't have Mr Zuckerberg here today which is incredible unfortunate, and I think speaks to a failure to account for the loss of trust certainly across the globe with respect to Facebook and Facebook's users," Nathaniel Erskine-Smith, vice chair of the standing committee on access to information, privacy and ethics in the lower house of Canada's parliament, told Allan at the hearing.
He added: "In the Canadian context, it wasn't until recently that you started to notify Canadian users that their information was shared in the Cambridge Analytica context. And that sense of corporate responsibility particularly one of the immense power and profit of Facebook has been as empty as the chair beside you."
Facebook began notifying users whether their data had been wrongly shared with Cambridge Analytica back in April.